Effects of K doping on structure and magnetic transport properties of Sr2−xKxFeMoO6

Ordered double-perovskite oxides of Sr 2− x K x FeMoO 6 (0.00   ⩽   x   ⩽   0.10) are synthesized via sol–gel method. X-ray powder diffraction analysis shows that all the samples have a single phase and exhibit I4/m symmetry. The cation order of Sr 2− x K x FeMoO 6 decreases from 94.4(2)% to 50.4(2)%, indicating that Fe/Mo is in nearly complete disorder. The magnetic property of Sr 2− x K x FeMoO 6 samples depends on temperature under zero-field-cooling (ZFC) and field-cooling (FC) processes at an applied magnetic field of 100   Oe. The thermal irreversibility behavior in the FC and ZFC curves indicates a typical cluster glass behavior in this system. The H / M versus M 2 curves indicate a second-order magnetic transition, resulting in a small variation in magnetic entropy. Antisite defect is the primary reason for the effective paramagnetic moment.